醋栗miRNAs的鉴定及表达研究

MicroRNAs (miRNAs) are a class of single-stranded, endogenous, small non-coding RNAs, which serve as regulators of gene expression to perform important functions in plant biological and metabolic processes. Although numerous miRNAs have been identified in many plant species, miRNAs still keep unknown in Ribes, which are economically important small fruit crops. In this study, an EST-based comparative genomics approach was employed to identify miRNAs from Ribes. According to a series of filtering criteria, 3 miRNAs were identified from 8,496 Ribes ESTs and were designated as ram-miR5021, rni-miR5021 and rni-miR5185. Subsequently, the 3 MIR genes encoding rni-miR5021and rni-miR5185 were cloned and transferred into Arabidopsis, and the accumulations of miR5021 and miR5185 were significantly produced in transgenic Arabidopsis, suggesting that these putative MIR genes identified from Ribes were able to generate their corresponding miRNA in vivo. Furthermore, the expression patterns of the Pre-miRNAs and accumulations of mature miRNAs in different tissues of Ribes were examined by qRT-PCR approach. These findings will greatly facilitate future studies on the functions and regulatory mechanisms of miRNAs in Ribes.